Blister on palm with an upcoming match!

After playing this weekend with a new racket (Leather grip with an Super Grap overgrip), I developed a rather large blister in my palm from holding the end of the grip in the base of my hand. The blister popped and now it hurts quite a bit to hold a racket. I have an upcoming doubles match this weekend, and would not like to cancel.

Any suggestions to help speed it's recovery? What about future prevention?